With the help of new studies, US researchers could have discovered the cause of severe courses of Covid-19 – in our own immune system.
Why do some people get Covid-19 much more seriously than others? This is one of the questions that research on the subject of coronavirus continues to this day. US researchers could now have come one step closer to answering this question: According to n-tv, two new studies were published in the specialist magazine "Science", which the authors assume that the lack of certain proteins known as type I interferons (IFN) could be the cause of severe Covid-19 courses. Infected cells make these proteins to prevent the viruses from spreading further. IFNs are part of the innate immune system and are part of the body's first defense step in the fight against infection.
Immune system sabotages itself
In study one, the researchers found so-called autoantibodies against interferons in more than ten percent of all seriously ill patients. These are misdirected antibodies that attack your own immune system and not the viruses. It was also noticeable that the absolute majority of those affected (94 percent) were men. This could also explain why men tend to be more seriously ill than women. It has not yet been possible to rule out whether the autoantibodies are a consequence of the infection
The first study was followed by a second, in which seriously ill patients were examined for genetic abnormalities. The focus was on 13 genes that are known to play a role in the immune defense against flu viruses and control type I interferons. Here it turned out that the patients with severe disease had genetic mutations, that interfere with the functioning of IFN. In total, blood samples from more than 650 patients with severe disease as well as from 530 patients without symptoms or with benign infections were analyzed.
When does Covid-19 become life-threatening?
The researchers derived from both studies, that seriously ill people either did not have type I interferon because it was completely neutralized by autoantibodies, or that it was not sufficiently produced due to an existing gene mutation. Jean Laurent Casanova, director of the St. Giles Laboratory of Human Genetics of Infectious Diseases at Rockefeller University in New York, who was involved in both studies, said of the results in a statement from the university: "These results provide compelling evidence that the disruption of type I interferon is often the cause of the life-threatening Covid-19. "